Golf Putter

ABSTRACT

A golf putter head having adjustability in weight and center of gravity. The putter head has a ball-striking front portion with a club face defining its width and height, a heal, a toe, and top and bottom surfaces defining the length of the front portion. The putter head has a front central axis extending through the center of gravity of the front portion and parallel to the top and bottom surfaces. A weight-and-balance-adjustment rear portion is connected to the front portion, which has a plurality of lengthwise-extending housings. Each housing includes an internal cavity constructed and arranged to removably contain at least one weighted slug. The putter head has a first center of gravity when the internal cavities are empty. The first center of gravity can be moved along the length, width and height of the putter by inserting weighted slugs in one or more of the cavities.

FIELD OF THE INVENTION

The present invention relates to the game of golf and golf clubs. More particularly, the invention relates to golf putters and methods of improving putting by changing the center of gravity of the putter head.

BACKGROUND OF THE INVENTION

Putting is an important part of golf where many extra strokes are unhappily added to the golfer's score. Controlled elements of producing a good, accurate putt include the golfer's stance, club head alignment and movement, and club head construction. Good putting requires consistently striking the golf ball squarely with the face of the putter. It has been found that the putter head weighting, including the location of the putter head's center of gravity, can be critical to consistently achieving accurate putting.

In an ideal, perfectly-executed putt, a golfer strikes the ball precisely on the sweet spot of the club face of the putter head. Such a perfect, sweet-spot shot keeps the putter head from twisting, and helps move the golf ball along the desired path to the hole. On the other hand, a putt that misses the sweet spot causes error proportional to the distance between the sweet spot and the golf ball's point of impact on the club face. And the longer the putt, the more pronounced the error gets, likely missing the hole.

This all-important sweet spot, however, is rarely at the spot marked by the manufacturer of the putter, usually at the geometric center of the club face, because it is often affected by the location and weight of the hosel and shaft or other factors that affect the putter head's weight distribution. Instead, the sweet spot is the exact spot on the club face where if a ball hits it, the club does not twist because it has equal weight on either side of the club. And a plane orthogonal to the club face that passes through the sweet spot necessarily passes through the center of gravity. Therefore, the location of the center of gravity of the putter head affects the location of its sweet spot.

Moving the center of gravity lower and to the back from the club face makes the club more forgiving, suitable for beginners, since it reduces the amount of twist when the ball misses the sweet spot, often described in the golf literature as enlarging the sweet spot. On the other hand, advanced players, who can hit the sweet spot more consistently, may prefer the center of gravity to be higher and closer to the club face, giving them more control and a precise feel.

Another way to make a club more forgiving is to place heavier material in the areas close to the edges of the club face (toe and heel of the club) than in the center of the club face. By adding more weight to the edge areas of the club face, the amount of twist that results from missing the sweet spot is reduced, again “enlarging the sweet spot” and making it easier for beginner players. Therefore, it would be desirable to provide a putter that can be customized by moving its center of gravity in all three dimensions as well as distributing weight to different positions of the golf club to accommodate an individual golfer's putting style, preferences, and competence.

SUMMARY OF THE INVENTION

The invention provides a putter head that can be customized to an individual golfer by adjusting the weight and location of the center of gravity of the putter head. This adjustability aids in the proper alignment with the golf ball. The invention employs a weighting system that permits the adjustment of weight distribution, hence the positioning of the putter head's center of gravity. Visual aspects of the putter head aid the golfer in properly aligning the putter head's striking face with the golf ball to achieve the desired path the ball will take to the hole.

Generally described, the golf putter of the present invention is a mallet-type putter with a putter head that has a substantial portion of its body extending rearward of the club face. The body of the putter head has a top surface crown and a sole opposite the crown which lies parallel to the ground when the putter head is grounded. The putter head has a front striking face or area for contacting the golf ball during the putting stroke. The putter head body is a unitary structure machined from a single block of aluminum.

In one preferred embodiment, the golf putter head comprises a front, ball-striking portion and a rear weight-and-balance adjustment portion. The ball-striking front portion has a club face defining the width and height of the putter head, a heal, a toe, and top and bottom surfaces defining the length of the front portion, and a front central axis extending through the center of gravity of the front portion and parallel to said top and bottom surfaces. The weight and balance-adjustment rear portion is connected to said front portion and has a plurality of lengthwise-extending housings relative to the club face. Each housing including an internal cavity with a cavity central axis and is constructed and arranged to removably contain at least one weighted slug. The putter head has a first center of gravity when the internal cavities are empty. The first center of gravity can be moved along the length, width and height of the putter by inserting weighted slugs in one or more of the cavities.

In preferred embodiments, the central axis of at least one of the plurality of housings is arranged at a different height, and the central axis at least one of the plurality of housings is arranged at a different width, relative to the central axis. Preferably, the central axis of each of the cavities is parallel to the front central axis, and the plurality of housings are symmetrically arranged about the front central axis.

The putter head includes a plurality of metal slugs, each having a shape and size that complements the shape and size of the cavities. The slugs have the same size but at least one slug has a different weight than another slug. The cavities include removable end caps for inserting or removing said slugs from the cavities.

The putter head preferably has a runner fixed to the bottom of a plurality of the housings and extending generally parallel to the front central axis. The runners resist rotation of said putter head by their frictional pressure against the ground when said putter head is grounded.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top, front perspective view of a putter head in accordance with one preferred embodiment of the invention;

FIG. 2 is a top, rear perspective view of the putter head of FIG. 1 ;

FIG. 3 is a bottom rear perspective of the putter head of FIG. 1 ;

FIG. 4 is a back plan view of the putter head of FIG. 1 ;

FIG. 5 is a side elevation of the putter head of FIG. 1 ;

FIG. 6 is a top rear perspective view of the putter head of FIG. 1 showing the weight slugs disassembled and removed from their respective housings;

FIG. 7 is a sectional perspective view of the putter head of FIG. 1 showing the weights slugs positioned inside the weight housings;

FIG. 8 is an enlarged front plan view of the face of the putter head of FIG. 1 ; and,

FIG. 9 is a golf club incorporating the putter head of FIG. 1 .

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

For the purpose of illustrating the invention, several embodiments of the invention are described with respect to the accompanying drawings. However, it should be understood by those of ordinary skill in the art that the invention is not limited to the precise arrangements and instrumentalities shown therein and described below. Throughout the specification, like reference numerals are used to designate like elements.

A golf putter in accordance with preferred embodiments of the invention is shown in FIGS. 1-9 and is designated generally by reference numeral 6. The putter 6 generally comprises a putter head 7 and a shaft 8, which is connected to the head 7 by a hosel 9. In preferred embodiments, the hosel 9 is fixed, preferably by gluing, in a socket (not shown) in the top of the putter head 7. The bottom of the shaft 8, which is usually hollow, is installed over and adhered to the hosel 9. The outer surface of the hosel 9 preferably has a shape that complements and is slightly smaller than the shape of the inner surface of the shaft 8 so that the shaft fits snugly on the hosel even without an adhesive.

The hosel may be fixed at numerous locations along the top of the first putter head depending on the golfer's preference. In FIGS. 1-9 , the hosel is shown located near the heel 17 for a right-handed golfer. However, in preferred embodiments, the lengthwise axis of the shaft should extend or project as close as possible through the center of the putter head; therefore, if the hosel is located near the heel, a shaft having a bottom offset or bend at the bottom should be used.

In one preferred embodiment shown in FIGS. 1-9 , the putter head 7 generally comprises a ball-striking front portion 11 and a weight-and-balance-adjustment rear portion 13. As used herein, the terms front and back are used with reference to a golf ball with which the putter is intended to be used. In preferred embodiments, the front and rear portions are integrally formed from a single mass of material; however, the front 11 and rear 13 portions could may be formed from separate components.

Referring to FIG. 1 , the front portion 11 of the putter resembles a blade-type putter and has a ball-striking face 15, heel 17, toe 19, top surface 21 and bottom surface 23. With reference to FIGS. 1 and 8 , the heel 17 and toe 19 define the width “W” while the top surface 21 and bottom surface 23 define the height “H” of the front portion 11, which are generally constant in the front portion 11. The depth “D” of the front portion 11 is defined by the distance from the front face to the interface between the front 11 and rear portions. The length L1 of the front portion 11 is slightly larger at the bottom compared to the top due to a slight loft on the face 15, described below.

As best seen in FIG. 8 , the face 15 is oval but may have a wide variety of other shapes and sizes. The face 15 has a textured surface to increase the amount of friction between the face 15 and the golf ball, which gets the golf ball rolling forward sooner than a smooth-faced putter. In one preferred embodiment, the surface of the face 15 does not have a uniform texture across the entire face 15; instead, the central portion 15 a of the face has a pattern of protruding dimples formed in the shape of a truncated starburst. In this portion, the dimples are arranged in a cross-hatched pattern to form the starburst shape. The texture of the remaining corner portions 15 b is formed by a pattern of horizontally-extending grooves 18. Preferably, the dimples and grooves are etched or machined into the putter face 15. In use, the preferred point of contact between the golf ball and the putter face 15 is at the central portion 15 a.

Although textured, the face 15 of the putter is generally planar but oriented at a slight upward loft angle as best seen in FIG. 5 to give the golf ball a slight lift when struck. Preferably the loft of the club face 15 complies with United States Golf Association (“U.S.G.A.”) regulations, which currently limit the loft to minus 15 degrees (negative loft) to positive 10 degrees. In preferred embodiments, the loft angle ranges from zero to positive 10 degrees. In the embodiment shown in FIGS. 1-9 , the loft angle is about 1.8 degrees from vertical.

In a preferred embodiment, the front portion 11 of the putter head is a generally solid mass of metal having sufficient weight to provide good swing momentum. The top surface 21 and bottom surface 23 are generally planar and parallel to one another. The heel 17 and toe 19 are curved in a semi-circular shape but may have any aesthetically-pleasing shape. The front portion 11 has a central axis “A” that also extends through the center of gravity of the head 7 when the cavities (described below) are empty. The central axis “A” also extends generally parallel to the plane of the top and bottom surfaces. The central axis “A” is widthwise centrally located between the heel 17 and the toe 19; however, because the face 15 of the putter is slightly inclined, the height of the center of gravity (as measured from the bottom surface 23) of the front portion 11 is lower than the height of the centroid of the putter face 15. A line normal to the centroid of the face 15 would extend skew to the central axis “A”.

The weight-and-balance-adjustment rear portion extends from the back side of the front portion 11, i.e., opposite the face 15. In one preferred embodiment, the rear portion generally comprises a trifurcated housing having three structures, which are integrally formed with one another and which extend rearward from the front portion 11 of the putter head 7. In this preferred embodiment, the rearward-extending structures comprise a pyramidal center housing 28, a two substantially-cylindrical side housings 24, 26 arranged on opposed sides of the center housing 28 proximal the heel 17 and toe 17, respectively. Each housing 24, 26, 28 has a central axis extending from the front to the back of the putter head, and an internal, cylindrical cavity or tube, 30, 32, 34, respectively, oriented along its central axis. In preferred embodiments, the axis of each housing and the axis of each cavity are co-axial. Preferably, the axis of all three housings extends parallel to the central axis “A” of the front portion 11.

In a preferred embodiment, the axis of the center housing is also widthwise centered along with the central axis “A” but is lower (toward the bottom) than the central axis “A”. The central axis of the heel housing 24 and toe housing extend through the face 15 proximate the heel and toe of the putter head, respectively, at a location higher than the central axis “A”. Preferably, the heel 24 and toe 26 housings are equidistantly spaced from the central housing 28, thereby providing a widthwise-extending balanced and symmetrical design. In a preferred embodiment, the axes of the heel and toe housings 24, 26 are not co-planar with the axis of the central housing 28, but instead lie above it as best seen in FIG. 4 . As described below, this arrangement allows for adjustment of the center of gravity of the putter head in all three dimensions.

In a preferred embodiment, the center housing 28 has the shape of a truncated irregular pyramid with triangulated top 28 a and bottom 28 b surfaces and rectangular side surfaces 28 c, 28 d. The cylindrical side housings 24, 26 have a frustoconical shape whose outer surface 24 c, 26 c tapers inwardly (reduced diameter) from the front end 24 a, 26 a abutting the front portion 11 to the back end 24 b, 26 b.

In preferred embodiments, each side housings 24, 26 includes an axial runner 36, 38, respectively, integrally formed on the bottom. The central axis of the runners 36, 38 is preferably parallel to the axis of its respective housing 24, 26. In a preferred embodiment, at least a portion of the bottom surface 36 a, 38 a of each runner 36, 38 is contiguous and coplanar with the bottom surface 23 of the front portion 11. When the putter head 7 is grounded, such as when the golfer releases his or her grip, the runners 36, 38 resist unwanted rotation of the putter head 7 because of their frictional pressure against the ground. The bottom surface 28 b of the central housing 28 is also contiguous with the bottom surface of the front portion 11 but preferably lies in a plane slightly skew to the plane of the bottom surface 23. Together, the bottom surface 23 of the first portion, bottom surfaces 36 a, 38 a of the runners 36, 38, and bottom surface 28 b of the center housing 28 form the putter sole.

In preferred embodiments, an alignment groove 40 is applied to the top of the putter head, which may be painted for higher visibility. The alignment groove 40 functions as a visual alignment aid and lies above the central axis “A” and along the center of gravity of the putter head when the cavities (described below) are empty or equally weighted in a balanced configuration. The ideal striking point on the club face 15 theoretically lies on the intersection of the central axis “A” and the club face 15.

Referring to FIGS. 6 and 7 , the internal cavities 30, 32, 34 are constructed and arranged to contain a plurality of weighted slugs having a shape and size that closely complements the internal shape and size of the cavities for snug fitting. In accordance with preferred methods of the invention, the weighted slugs 42 can be inserted in one or more of the cavities to change the overall weight of the putter head as well as the center of gravity of the putter. Because the cavities extend along the central axis “A” and length of the putter, and because the cavities are located at different heights within the putter and at different widths, the center of gravity of the putter can be changed in all three dimensions by varying the number and location of weights within the cavities. For example, the center of gravity of the putter can be moved rearwardly or forwardly by adding weights along the length of any one of the cavities. The center of gravity can be moved toward the toe by adding more weight to the toe cavity 32, or adding weight only to the toe cavity 32. The center of gravity can be moved lower by adding more weight to the center cavity 34, or adding weight only to the center cavity 34. The use of multiple housings and their positioning on the putter head provide endless possibilities for repositioning the center of gravity forward or rearward, higher or lower, or from side to side.

Each cavity includes a removable cap 44 at its back end to access the cavity and secure the slugs 42 therein. In one preferred embodiment, the caps 44 are threaded plugs that screw into a complementary threaded back end portion of the cavity. An optional spring or elastomeric washer is provided in between the end cap 44 and the slugs 42. Once inserted and tightened, only the head end of the cap is visible from a rear end view of the putter, which enhances the overall aesthetic quality of the putter.

In the embodiment shown in FIGS. 1-9 , each housing cavity holds up to three (3) slugs as best seen in FIGS. 6 and 7 ; however, that capacity can change by varying the size of the slugs, changing the length of the cavity, or both. For more precise adjustment/tuning of the center of gravity of the putter, the weighted slugs 42 are made from a variety of materials and therefore have different weights. The differently-weighted slugs 42 are preferably identified using some form of alpha numeric indicia or symbol. For example, referring to FIG. 6 , the weighted slugs having no annular ring on their outer surface 42 a are made from tungsten alloy, while those with one ring 42 b are made from 304 stainless steel, and those with two rings 42 c are made from 6061 aluminum. In this embodiment, the weighted slugs range in weight from about 0.3 to about 0.8 ounces. Optionally, an unweighted slug is inserted as a spacer if the golfer desires less weight provided by three of the lightest weighted slugs. As used herein with respect to the illustrated preferred embodiments, a weighted slug weighs more than about 0.1 ounce while an unweighted slug or spacer weighs less than about 1 ounce.

The sectional plan view of the putter head 7 from above shows the orientation of the weighted slugs 42 in their respective housing tubes and secured by the endcaps 44. The removable, weighted slugs 42 and their housing cavities 30, 32, 34 are aligned in parallel with each other and with the central axis “A”. The weighted slugs 42 in the center housing 28 are positioned slightly rearward of the slugs in the two side housings 24, 26. Preferably, the weighted slugs 42 are aligned substantially perpendicular to the plane of the club face 15 as seen FIG. 6 .

In a preferred embodiment, the putter head 7 is machined from a solid billet of aluminum as opposed to being cast or forged into shape. From a solid block it is then CNC milled into shape as a single-body unit. The four holes on the bottom shown in FIG. 3 are used for fixturing during machining, anodizing and assembly to ensure the shaft is aligned correctly. Once machining is complete, the four holes are closed using aluminum plugs 48, which are glued or threaded in place to make up for the weight loss and hide the holes.

In other embodiments, the rear portion may comprise more or less than three elongate housing structures so long as the structures enable the balance-adjustment features described above. Preferably, those structures should be balanced about a central axis “A” so that the putter center of gravity lies along or close to the central axis “A” when the cavities of those structures are empty.

It is understood that there may be many variations and modifications of the above-described embodiment which do not depart from the scope and spirit of the invention. For example, multiple weights can be any number and constructed from any suitable material. Similarly, the body of the putter head (9) described here is composed of aluminum but other materials and methods of manufacture could be employed. Furthermore, the club face texture could be slotted or have any pattern desired. Other modifications or adaptations may be devised by those of skill in the art of golf club design. 

1. A golf putter head comprising: a. a ball-striking front portion having a club face defining the width and height of said putter head, a heal, a toe, and top and bottom surfaces defining the length of said front portion, and a front central axis extending through the center of gravity of said front portion and parallel to said top and bottom surfaces; b. a weight and balance-adjustment rear portion connected to said front portion having a plurality of lengthwise-extending housings relative to said club face, each housing including an internal cavity with a cavity central axis and constructed and arranged to removably contain at least one weighted slug, wherein said putter head has a first center of gravity when said internal cavities are empty, and, wherein said first center of gravity can be moved along the length, width and height of said putter by inserting weighted slugs in one or more of said cavities.
 2. The golf putter head recited in claim 1, wherein the central axis of at least one of said plurality of housings is arranged at a different height, and the central axis at least one of said plurality of housings is arranged at a different width, relative to said central axis.
 3. The golf putter head recited in claim 2, wherein the central axis of each of said cavities is parallel to said front central axis.
 4. The golf putter head recited in claim 1, wherein said plurality of housings are symmetrically arranged about said front central axis.
 5. The golf putter head recited in claim 1, including a plurality of metal slugs, each having a shape and size that complements the shape and size of said cavities.
 6. The golf putter head recited in claim 6, wherein said slugs have the same size but at least one slug has a different weight than another slug.
 7. The golf putter head recited in claim 1, wherein said cavities include removable end caps for inserting or removing said slugs from said cavities.
 8. The golf putter head recited in claim 1, further comprising a runner fixed to the bottom of a plurality of said housings and extending generally parallel to send front central axis.
 9. The golf putter head recited in claim 8, wherein said runners resist rotation of said putter head by their frictional pressure against the ground when said putter head is grounded.
 10. The golf putter head recited in 1, wherein said front portion and back portion have a unitary construction.
 11. The golf putter head recited in claim 1, including a center housing extending laterally rearward from and integral formed with said front portion and equidistantly-opposed side housings extending laterally rearward from and formed integral with said front portion.
 12. The golf putter head recited in claim 11, wherein said side housings are symmetrically positioned about said center housing and parallel to each other.
 13. The golf putter head recited in claim 11, wherein said center housing is positioned more rearward and closer to the bottom of the putter head than said side housings.
 14. The golf putter head recited in claim 1, wherein said club face has a first textured surface on its face in a ball striking area, and a second textured surface outside of the ball striking area. 